Department of Emergency Medicine, College of Medicine, Chungbuk National University, 410 Seongbong-Ro, Heungduk-Gu, Cheongjoo 361-763, South Korea.
Brain Res. 2012 Apr 4;1447:91-105. doi: 10.1016/j.brainres.2012.01.049. Epub 2012 Jan 28.
[d-Ala2, d-Leu5] enkephalin (DADLE) is a synthetic δ-opioid agonist that induces hibernation and promotes survival of neurons and glial cells in the central nervous system. Several mechanisms for the attenuation of hypoxic injury have been suggested, including control of intracellular signaling pathways via the δ-opioid receptor (DOR). However, the cellular and molecular mechanisms of DADLE in hypoxic injury are largely unknown. To investigate neuronal injury after oxygen-deprivation (OD) and DOR stimulation by DADLE, we used a lactate dehydrogenase assay, MTT assay, and immunofluorescence live/dead staining. And we used cDNA microarrays to investigate the influence of DADLE exposure on transcription after OD in rat cortical glial and neuronal co-culture. DADLE reduced neuronal injury after 24 h of OD. Preconditioning with DADLE before 24 h hypoxia exposure also altered gene expression in comparison with 24h OD without pretreatment. After DADLE exposure and hypoxia, 1917 of 39,511 genes (4.9%) were significantly induced or repressed at least 2.5-fold. Assigning differentially expressed ESTs (expressed sequence tags) to molecular functional groups revealed that DADLE affected many pathways including apoptosis, intracellular ion homeostasis, molecular chaperones, and glucose metabolism. We observed a coordinated change in expression of many genes (increased expression of potentially protective genes and decreased expression of potentially harmful genes) after DADLE exposure. A comprehensive list of regulated genes should prove valuable in advancing our understanding of the neuroprotective mechanisms of DADLE under OD.
[D-ala2，D-leu5]脑啡肽（DADLE）是一种合成的 δ 阿片受体激动剂，可诱导休眠并促进中枢神经系统神经元和神经胶质细胞的存活。已经提出了几种减轻缺氧损伤的机制，包括通过 δ 阿片受体（DOR）控制细胞内信号通路。然而，DADLE 在缺氧损伤中的细胞和分子机制在很大程度上尚不清楚。为了研究缺氧剥夺（OD）后神经元损伤和 DADLE 对 DOR 的刺激作用，我们使用乳酸脱氢酶测定法、MTT 测定法和免疫荧光死活染色法进行研究。并且我们使用 cDNA 微阵列研究了 DADLE 暴露对大鼠皮质神经胶质和神经元共培养物 OD 后转录的影响。DADLE 可减少 24 小时 OD 后神经元损伤。与没有预处理的 24 小时 OD 相比，24 小时缺氧暴露前用 DADLE 预处理也改变了基因表达。DADLE 暴露和缺氧后，在 39511 个基因中（4.9％）有 1917 个基因的表达至少被 2.5 倍诱导或抑制。将差异表达的 EST（表达序列标签）分配到分子功能组中表明，DADLE 影响了许多途径，包括细胞凋亡、细胞内离子稳态、分子伴侣和葡萄糖代谢。我们观察到 DADLE 暴露后许多基因的表达发生了协调变化（潜在保护性基因的表达增加和潜在有害基因的表达减少）。调节基因的综合列表应有助于深入了解 DADLE 在 OD 下的神经保护机制。
